In countries like the United States where meat is not as expensive, though, people often choose to be vegetarians for reasons other than cost. Parental preferences, religious or other beliefs, and health issues are among the most common reasons for choosing to be a vegetarian. Many people choose a vegetarian diet out of concern over animal rights or the environment. And lots of people have more than one reason for choosing vegetarianism.

Vegetarian and Semi-Vegetarian Diets

Different people follow different forms of vegetarianism. A true vegetarian eats no meat at all, including chicken and fish. A lacto-ovo vegetarian eats dairy products and eggs, but excludes meat, fish, and poultry. It follows, then, that a lacto vegetarian eats dairy products but not eggs, whereas an ovo vegetarian eats eggs but not dairy products.

A stricter form of vegetarianism is veganism (pronounced: VEE-gun-izm). Not only are eggs and dairy products excluded from a vegan diet, so are animal products like honey and gelatin.

Some macrobiotic diets fall into the vegan category. Macrobiotic diets restrict not only animal products but also refined and processed foods, foods with preservatives, and foods that contain caffeine or other stimulants.

Following a macrobiotic or vegan diet could lead to nutritional deficiencies in some people. Teens need to be sure their diets include enough nutrients to fuel growth, particularly protein and calcium. If you're interested in following a vegan or macrobiotic diet it's a good idea to talk to a registered dietitian. He or she can help you design meal plans that include adequate vitamins and minerals.

Some people who have eliminated red meat but may eat poultry or fish consider themselves semi-vegetarians.

Are These Diets OK for Teens?

In the past, choosing not to eat meat or animal-based foods was considered unusual in the United States. Times and attitudes have changed dramatically, however. Vegetarians are still a minority in the United States, but a large and growing one. The Academy of Nutrition and Dietetics (AND) has officially endorsed vegetarianism, stating "appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases."

So what does this mean for you? If you're already a vegetarian, or are thinking of becoming one, you're in good company. There are more choices in the supermarket than ever before, and an increasing number of restaurants and schools are providing vegetarian options — way beyond a basic peanut butter and jelly sandwich.

If you're choosing a vegetarian diet, the most important thing you can do is to educate yourself. That's why the AND says that a vegetarian diet needs to be "appropriately planned." Simply dropping certain foods from your diet isn't the way to go if you're interested in maintaining good health, a high energy level, and strong muscles and bones.

Vegetarians have to be careful to include the following key nutrients that may be lacking in a vegetarian diet:

iron

calcium

protein

vitamin D

vitamin B12

zinc

If meat, fish, dairy products, and/or eggs are not going to be part of your diet, you'll need to know how to get enough of these nutrients, or you may need to take a daily multiple vitamin and mineral supplement.

Iron

Sea vegetables like nori, wakame, and dulse are very high in iron. Less exotic but still good options are iron-fortified breakfast cereals, legumes (chickpeas, lentils, and baked beans), soybeans and tofu, dried fruit (raisins and figs), pumpkin seeds, broccoli, and blackstrap molasses. Eating these foods along with a food high in vitamin C (citrus fruits and juices, tomatoes, and broccoli) will help you to absorb the iron better.

Girls need to be particularly concerned about getting enough iron because some iron is lost during menstruation. Some girls who are vegetarians may not get enough iron from vegetable sources and may require a daily supplement. Check with your doctor about your own iron needs.

Calcium

Milk and yogurt are tops if you're eating dairy products — although vegetarians will want to look for yogurt that does not contain the meat byproduct gelatin. Tofu, fortified soy milk, calcium-fortified orange juice, green leafy vegetables, and dried figs are also excellent ways for vegetarians (and vegans) to get calcium. Remember that as a teen you're building up your bones for the rest of your life.

Because women have a greater risk for getting osteoporosis (weak bones) as adults, it's particularly important for girls to make sure they get enough calcium. Again, taking a supplement may be necessary to ensure this.

Vitamin D

We need vitamin D to get calcium into our bones. Your body manufactures vitamin D when your skin is exposed to sunlight. Cow's milk is top on the list for food sources of this vitamin. Vegans can try fortified soy milk and fortified breakfast cereals.

Some people may need a supplement that includes vitamin D, especially during the winter months. Everyone should have some exposure to the sun to help the body produce vitamin D.

Protein

Before, it was thought that vegetarians needed to combine incomplete plant proteins in one meal — like red beans and rice — to make the type of complete proteins found in meat. We now know that it's not that complicated. Current recommendations are that vegetarians eat a wide variety of foods during the course of a day.

Eggs and dairy products are good sources of protein, but also try nuts, peanut butter, tofu, beans, seeds, soy milk, grains, cereals, and vegetables to get all the protein your body needs.

Vitamin B12

B12 is an essential vitamin found in animal products, including eggs and dairy. Fortified soy milk,fortified breakfast cereals, and nutritional yeast also have this important vitamin. It's hard to get enough vitamin B12 in your diet if you are vegan, so a supplement may be needed.

Zinc

If you're not eating dairy foods, make sure fortified cereals, dried beans, nuts, and soy products like tofu and tempeh are part of your diet so you can meet your daily requirement for this important mineral.

Fat, Calories, and Fiber

In addition to vitamins and minerals, vegetarians need to keep an eye on their total intake of calories and fat. Vegetarian diets tend to be high in fiber and low in fat and calories. That may be good for people who need to lose weight or lower their cholesterol but it can be a problem for kids and teens who are still growing and people who are already at a healthy weight.

Some vegetarians (especially vegans) may not get enough omega-3 fatty acids. Omega-3 fats are good for heart health and are found in fish and eggs. Plant sources of omega-3 fatty acids include some vegetable oils, (such as soybean, canola, and flaxseed), chia seeds, ground flax seeds, and walnuts.

High-fiber diets tend to be more filling, and as a result strict vegetarians may feel full before they've eaten enough calories to keep their bodies healthy and strong. It's a good idea to let your doctor know that you're a vegetarian so that he or she can keep on eye on your growth and make sure you're still getting adequate amounts of calories and fat.

Getting Some Guidance

If you're thinking about becoming a vegetarian, consider making an appointment to talk with a dietitian who can go over lists of foods that would give you the nutrients you need. A dietitian can discuss ways to prevent conditions such as iron-deficiency anemia that you might be at an increased risk for if you stop eating meat. Ask your doctor or dietitian if you need to take a daily multivitamin or other supplement.

Tips for Dining Out

Eating at restaurants can be difficult for vegetarians sometimes, but if you do eat fish, you can usually find something suitable on the menu. If not, opt for salad and an appetizer or two — or ask if the meat can be removed. Even fast-food places sometimes have vegetarian choices, such as bean tacos and burritos, veggie burgers, and soy cheese pizza.

You may also find that the veggie burgers, hot dogs, and chicken substitutes available in your local grocery store taste very much like the real thing. Try the ground meat substitute as a stand-in for beef in foods like tacos and spaghetti sauce.

Regardless of whether you choose a vegetarian way of life, it's always a healthy idea to eat a wide variety of foods and try out new foods when you can.